Artificial limb



Nov. 20, 1928.

H. w. KARN ARTIFICIAL LIMB Filed Jan. 7, 1925 IN V EN TOR.

Patented Nov. 20, 1928.

Tnn'nnx w. man, or" PITTSBURGH,IJPENNSYLVANIA.

7 ARTIFICIAL LIMB.

-App1icat1on filed January 7, 192a swarm; 997.

My invention refers to improvements ar-- tificial limbs, more especially an artificial? articulated leg, consisting of;an upperthigh portionadapted to form a receiving connectmgreceptacle for the. stump of the human limb, and having av lower; portion. pivotally connected to swing at the knee joint. l The improvement consists in providing between the. upper and lower articulated sections, flexible tension w exerting members adapted tobe-operatedby the user and exerting a swinging action on thelowerv section, constructed and operating in the ,manner hereinafter described. Y

Fig. 3 is a partial View in front elevation,

SllOWlIlg the knee joint Fig. 4 is a similar view. rom the-rear. l The artificial leg members A'B are'of generally usual construction, made of wood, or other suitable light strong material, both membersbeinghollow; Theupper or thigh member A isprovided at its upper portlon with a receiving terminal cavity a adapted to fit closely around thestump ofthe amputated limb, and to be held thereon by the tens on of the supporting and connecting elements hereinafter described. i i ,3 .j

The lower or shin member is pivotally connected .by bolt 2:.with-the upper member A, in the usual manner, whereby the two members 7 are, articulated to, provide the hinged knee joint, in a manner commonly practiced in this art. The lower outer front portion of the upper member A is rounded, as indicated at 3, and fits neatly w1th1n the upper front tapering edge portion 4 of the member B, providing for a small overlapping extension of the members in varylng pos1- tions.

In addition to the hinged connection by bolts 2, the two members are braced in the rear thereof by flexible connections 5 of rawhide or other suitable material, disposed at each sideofthe vertical center, as-in 4," :1 connected at opposite ends by cross bolts or 7 pins 6.7, respectively,and passing through suitable clearance, grooves in:- the upper .mem-i ber. Such connectlons 5 easily-flex on -back-' ward swinging of lower member B, as in Fig.

2, butbrace said member against forward swinging beyond anormal longitudinal ex,-

tension, so as to preventbuckling at the knee, joint ,or flexibility other than in a back-ward direction. Incidentally, the object in view is topermit easy reverse swinging and to prevent undue forward swinging, under the ten-,'

sion exertingpower of the operating straps; Such forward swinging is effectedthrough a pair. of tension straps or connections 85 8; .1 1 As shown, these extend upwardly beyond. the topof upper member A to a point where they are connected by loops or other suitable terminals 9 with the hooks or other connec tions 10 of thesuspender straps 11. Said straps, as shown, pass around from front to back over the shoulders of the wearer, as in Fig. 1, and are connected with theterminals of themembers 8 atfront and back under proper tension, such ten ulated by buckles 12;.

constitutes the power transmitting element, whereby to utilize the tension exerting effect ofv members 8. Such bolt. 13, as shown, i s located at a suflicient distance'below pivotal bolt 2 to ensure good leverage and for the purpose of providing an ample cylindrical bearing. for members 8, which may beof rawhide in strap form or of other s'uitable material, a spool 0r thimble bushingl l is used. I Said bushing, which may conveniently be of fibre or othersimila-r material, is ro-j ATE-NT Pica-1.

sion being easily reg-J Extending across theiniddle body portion, 7 oflower member B isa pin: or bolt 13, which.

tatably mounted around the boltl3 between the sides? of the hollow limb, extending across through .its hollow portion, providing for ample-bearingsurface of the pair of straps with ease and free rotation on the bolt.

A'similar bushingzor cylindrical bearing 15 is preferably mounted on pivotal bolt .2,

providing a rotatable bearing for the rear portions 8 of the strap members, If desired, however, the bolt 2 may be left bare, but the bushing 15 is of advantage in reducing friction. Said members pass outwardly through inclined front and back openings 1617 respectively, in the upper member A, such openings being sufliciently above the rounded knee portion to avoid any unnecessary interference or friction. The member 8 8" is preferably passed through suitable guiding loops or eyes 18 at the upper front and back portion ofmember A, so as to maintain it in normal position for easy and convenient connection with the terminals of the suspender supports It will be understood that .the 'two main members of the limb are properly constructed for easy and smoothinterfitting hinge action, ventilation of the interior, and cushloninggto 1e,

prevent shocks or jars, wherever desira and with proper clearance openings for'access to the interior wherenecessary. j

In using the device as constructed and above described, it is placed in firm attaching connection on the stump, the connections are made with the shoulder straps, and proper tension provided. In use, the desired swinging' tension is exerted by shoulder action of a the wearer, together with proper swin 'ng manipulation, to effect upward pulling o the front or back straps 8 or 8 in walking. Uponlifting the foot, such upward tension on the front straps tends to exert a forward pulling action on bolt 13, the rear member 8 being correspondingly relaxed so that the lower It will be understood that the devicemay be variously changed in proportions, construction of the detail parts, varied as to the material. used, or otherwise, by theskilled mechanic, but that all such changes are to be included as Within the scope of the following claims. i

I claim: 1. An artificial limb of the class described comprising a thigh member, a lower leg memher, a connecting knee joint pivot, inwardly extending pivot hearings on the thigh member, a roller on the pivot between said bearings, a cross bearingon the lower shin' mom"- berbelow the pivot, and a continuous tension member extending inwardly through the front of the thigh member and passing over i p beyond the pivot roller" amdaiwumd saidcross bearing, then again over the knee joint roller and outwardly through the back of the thigh member, and having connecting devices at its u per front and back ends;

2. arti cial limb of the class described comprising a thigh member, a lower shin member, a connecting knee joint pivot, inwardly extending pivot hearings on the thigh member, a roller on the" pivot between said bearings, a continuous cross roller bearing on the lower shin below the pived ahd a continuous tension member extendinginwe rdly through. the thigh member trout and back, over and in front of the pivot, and around said roller bearin V a a 1 3. An artificial limb the class described comprisinga thi h member hmvim'ginwardly extending pivot ea rings, alower sh i n mem ber, acct-meeting joint pivotmennted insaid inwardly extending bearings with terv'e'ning 1 clearance and rovided f with a middle continuous cross ro ler in said clear ance, a cross bar" in the lower shin member below the pivot having a th-imble bushing;

and a continuoustension member extending inwardl through the thigh member at front and hue over andi'n front of the pivot-bearing and around thevthimbl e bashing for exerting leverage action on the lower member, said tension member entending npw'ardly'at front and back and having connection with a shoulder strap. a r a g 4".- The combination with a hollow thigh member hav'i inwardly'extendi centrally spaced pivot rin s, and a hol"ow lower s in member pivot thereto and rewided with a cross bearingroie'ler below't pivot, said pivot'consistin Leia erosspin extending through the inwar =ydisposedhearings with an intervening rollerthereon, ofaparroi continuous substa-ntia parallel tension mam bers passing down irectl-y in front-and oppositely back of the thigh member, thea'inwardly at front and back above the joint, over and' in front ofthe' pivotal connection and over the bearing roller thereon between the pivotbearings of the thigh 'member "and aroundthe. cross bearing roller of the-shin member, and having separable connections at their upper outer ends at front and but with a pair of shoulder stras. a In testimony I hereunto mamsignature,

HARRY w. Ki an. i f 

